Do geographically widespread species of tropical amphibians exist? An estimate of genetic relatedness within the neotropical frogLeptodactylus fuscus(Schneider 1799) (Anura Leptodactylidae)

Abstract

Leptodactylus fuscus (Schneider 1799) as currently understood has a broad geographic range, extending from Panama to Argentina east of the Andes and on the islands of Trinidad and Tobago. We obtained 16 samples throughout its distributional range for electrophoretic analysis to obtain estimates of genetic differentiation within the taxon. Twenty-four loci were scored for analysis. Analytical techniques were used that were appropriate for analyzing inter-population variation of open genetic systems and genetic systems with reduced or no gene flow among populations. The techniques used are: multidimensional scaling; correlation of geographic and electrophoretic distances; gene flow estimates; phylogenetic techniques. The results indicate that the series of samples from Trinidad, Tobago, French Guiana, and Roraima, Brazil have low genetic distances that correspond to an isolation-by-distance model of differentiation, thus comprising a system of populations linked by gene flow within a single species. However, the samples from Panama and those south of the Amazon River demonstrate genetic partitioning, such that there is insignificant gene flow among some sets of these samples as well as with samples north of the Amazon River. Leptodactylus fuscus is a "weedy" species, characteristic of open habitats and able to colonize and survive in human altered habitats. Such a "weedy" species would be expected to have relatively low levels of genetic diversity, contrasting strikingly with the levels of genetic differentiation discovered in our study. If these results are typical for other neotropical frogs, we are currently grossly underestimating the amount of diversity in tropical frogs, which has obvious conservation consequences.

Cytogenetic and random ampliied polymorphic DNA analysis of Leptodactylus species from rural and urban environments (Anura, Amphibia)

“…The species L. fuscus has a wide geographical range (the greatest of the four species) and is considered an invader species (very generalist) with a moderate dispersion potential (Wynn and Heyer, 2001). The data obtained in the present study corroborate this hypothesis.…”

Herpetofauna do Parque Estadual Carlos Botelho, São Paulo, Brasil

“…No PECB machos foram encontrados vocalizando em áreas de pastagens longe de corpos de água permanente, na área 1. Segundo Wynn & Heyer (2001), a espécie ocupa ambientes abertos e se adapta bem aos ambientes modificados. Leptodactylus fuscus ocorre em regiões abertas, do Panamá ao Sul e Sudeste do Brasil, Bolívia e Argentina, a Leste dos Andes (Frost 2009).…”

Revealing cryptic diversity using molecular phylogenetics and phylogeography in frogs of the Scinax ruber and Rhinella margaritifera species groups

“…However, so little is known of the diversiWcation and age of lineages in Neotropical frog taxa that current spatial proximity between populations might also be the result of a long history of expansions and contractions of ranges. Geographic and genetic fragmentation is so common in tropical amphibians that Wynn and Heyer (2001) have questioned whether widespread species of tropical amphibians exist at all. Considering the eVects of global amphibian declines (Hanken, 1999;Houlahan et al, 2000;Stuart et al, 2004), numerous, still undescribed species are probably vanishing at alarming rates in the Neotropics.…”